Vision globe and method of illustrating visibility



A; M'.'PAT1'R'soN. JQ.' E1' AL v2,205,961

Jmme 25, 1940.

' vIsIoN sLoBE AND METHOD oF ILLUSTRATING VISIBILITY Filed Sept. 14, 1938 .iatented June 25, 1940 PATENT OFFICE" VISION GLOBE AND METHOD OF TRATING VISIBILITY Albert M. Patterson, Jr.,

ILLUS- and Nelson S. Riley, Jr.,

Buffalo, N. Y., assignors to Bell Aircraft Corporation, Buifalo, N. York 3 Y., a corporation ol' New v Application September 14, 1938, Serial No. 229,948

6 Claims.

This invention relates to a method and apparatus for illustrating the range of visibility for a person positioned at a point above the ground level, and more particularly to a method and r apparatus for illustrating the visibility in all directions afforded to the pilot of any typeY of aircraft.

One of the objects of lthis invention is to provide a globe in whichis mounted an `airplane model or other point of observation in such a manner that the eye of the observer whose vision is to be illustrated is theoretically located at the exact center of the globe.

Another object of our invention is to provide a l5 method of illustrating the visibility of the observer mentioned above by shading the portion of the globe which is normally invisibleto his sight.

A further object of our invention is to provide a method of locating the shaded areas on the globe `by constructing the airplane or other point of observation to scale and placing a light at the center of the globe, the shadows produced by the said airplane being at points which are invisible to the observers eye.

With these and other objectsin view, our invention consists in providing a globe in which is placed a scaled model of an airplane or other observation unit in which theoretically an obi server could be stationed. This s caled model is o mounted in the globe -in such a manner that the eye oi the observer is presumed to be in the exact centerof the globe.

As the model is constructed to scale, the visibil- 5 ity of the observer may be ascertained by placing a light at the normal position of the observers eyes and tracing the resulting shadows thrown on the globe. These shaded places coincide with the points which are invisible to the observer. o In the drawing the ligure illustrates a transparent or translucent hollow globe in which is mounted a model airplane constructed to scale.

As shown in the drawing a practical applica- 5 tion of our invention consists of a hollow transparent globe, generally indicated by the numeral l, in'which a model airplane 2 is mounted on a pedestal 3. 'I'his model airplane 2 is mounted in such a manner that the portion of the fuselage in which a pilot is usually mounted is positioned in the exact center of the globe. The range of visibility of the pilot is now indicated by painting or otherwise shading that portion of the globe which is not visible to the I pilot. The portion which should be shaded may be ascertained in any suitable manner, such as by placing a small light 4 at the-position normally occupied by theobservers eyes, that is, the exact center of the globe, and tracing the shadow thrown by the airplane. A horizontal s meridian line is also traced on the globe. This line is drawn through points which are on the same horizontal plane as the central point of the globe.

'I'he shaded portion is not the actual area which would be invisible from an airplane of the size of the scale model, as in order to determine the actual area it would be necessary to use a substantially plane surface. However, all-of the invisible area is included in the shaded area and this area may be used for determining the relative area of visibility of the scale model. This is especially important when the area of visibility of two or more scale mod els is being compared.

From the above description it is believed ob-` vious that the vision of an observer positioned at any part of an airplane may be tested by simply mounting the airplane in such a manner that the portion of the plane in which the observer whose vision is to be tested Iis located will be positioned directly'at the center of the globe. In a like manner, the zone of visibility, due to the use of a visible oor porthole in the'fuselage of the plane, may be shown on the globe.

The plane may be suspended in thecenter of the globe by the use of wires or any other suitso I able means, and in placeof an airplane a balloon or any other construction which would support an observer can be used.

From the above description it is believed apparent that the form of our invention shown in the drawing is merely to illustrate onepractical use of this invention, and that it is not intended lthat our invention be limited in any manner to the specic construction shown in this drawing. For this reason we wish it understoodl that We intend this application to be only limitedY by the .prior art and the scope of the appended claims.

We claim:

1. In a device for indicating the range of nonvisibility of an observer under actual conditions, the combination of a globe, a scale model of an observation structure positioned at the point of intersection of the central axes of the globe, a light source positioned at a point on the scale 50 model which corresponds to that occupied by the eye of an observer on the full sizedv observation structure, so as to cause a shadow on the interior surface of the globe.

2. In a device for indicating the range of nonvisibility of an observer under actual conditions, the translucent body, and a light source posithe combination of a globe, a scale model of an tioned at a point on the scale model which correairplane positioned at the point of intersection of sponds to that occupied by the eye of an observer the central axes of the globe, alight source posion a full size airplane, so as to cause a shadow 5 tioned at a point on the scale model which coron the interior surface of the body. 5 responds to that occupied by the eye of an ob- 5. The method of determining the relative server in the full sized airplane, and means to areas of non-visibility from a plurality of airlight so as to cause a shadow on the interior surplanes comprising the steps of successively placface of the globe. ing a scale model of each airplane within a trans- 3. In a device for indicating the range of nonlucent body, and then placing a light in the 10 visibility of an observer under actual conditions, model at the normal position of an observer the combination of a hollow translucent body thereby projecting the shadow caused by the having continuous Walls, a scale model of an obopaque portions of lthe model on the translucent servation structure positioned at approximately body.

the center of the translucent body, and a light 6. The method of determining the relative 15 source positioned at a point on the scale model areas of non-visibility from a plurality of obserwhich corresponds to that occupied by the eye vation structures comprising the steps of succesof an observer on a full size observation structure, sively placing a scale model of each observation so as to cause a shadow on the interior surface of structure within a translucent body and placing the body. a light in the model at the normal position of an 20 4. In a device for indicating the range ot nonobserver thereby projecting a shadow caused by visibility of an observer under actual conditions, the opaque portions of the model on the transthe combination of a hollow translucent body 4lucent body. having continuous walls, a scale model of an air- ALBERT M. PATTERSON, Ja.

plane positioned at approximately the center of NELSON S. RILEY, Jaz. 25 

